Flutter:TextField onChanged 处理程序默默吞下异常

Question

当 TextField.onChanged 中抛出异常且未处理时处理程序它不会冒泡到全局 Flutter.onError处理程序，所以它被默默地错过了。有没有办法全局处理这些错误，以便我至少知道它们在开发时被抛出？
它似乎被捕获并转换为 MethodChannel._handleAsMethodCall() 中的对象，但我不明白它是如何从那里处理的。

main() {
  runApp(Test());
}

class Test extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: TextField(
            decoration: InputDecoration(
              labelText: "Input",
            ),
            onChanged: (input) {
              throw Exception(); // <-------- swallowed by framework
            },
          ),
        ),
      ),
    );
  }
}

Answer 1

问题是你必须调用WidgetsFlutterBinding.ensureInitialized()在您分配自定义错误处理程序之前 - 以下代码适用于我:

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
void main() {
  WidgetsFlutterBinding.ensureInitialized(); // <- this needs to happen before assigning your error handler
  FlutterError.onError = (FlutterErrorDetails details) => print('custom error handling');
  runApp(Test());
}

class Test extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: TextField(
            decoration: InputDecoration(
              labelText: "Input",
            ),
            onChanged: (input) {
              print(input);
              throw Exception(); 
            },
          ),
        ),
      ),
    );
  }
}

写入 'uiae' 时的控制台输出:

Performing hot restart...
Syncing files to device Chrome...
Restarted application in 434ms.
u
custom error handling
ui
custom error handling
uia
custom error handling
uiae
custom error handling

您可能还想看看 Flutter: How to implement FlutterError.OnError correctly和 Flutter catching all unhandled exceptions因为它们似乎与您的问题有关。